/* VIPS function dispatch tables for image format load/save.
 */

/*

	This file is part of VIPS.

	VIPS is free software; you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	02110-1301  USA

 */

/*

	These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk

 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <glib/gi18n-lib.h>

#include <stdio.h>

#include <vips/vips.h>
#include <vips/internal.h>

/* To iterate over supported formats, we build a temp list of subclasses of
 * VipsFormat, sort by priority, iterate, and free.
 */

static void *
format_add_class(VipsFormatClass *format, GSList **formats)
{
	if (!G_TYPE_IS_ABSTRACT(G_OBJECT_CLASS_TYPE(format)))
		/* Append so we don't reverse the list of formats.
		 */
		*formats = g_slist_append(*formats, format);

	return NULL;
}

static gint
format_compare(VipsFormatClass *a, VipsFormatClass *b)
{
	return b->priority - a->priority;
}

/**
 * vips_format_map: (skip)
 * @fn: function to apply to each #VipsFormatClass
 * @a: user data
 * @b: user data
 *
 * Apply a function to every %VipsFormatClass that VIPS knows about. Formats
 * are presented to the function in priority order.
 *
 * Like all VIPS map functions, if @fn returns %NULL, iteration continues. If
 * it returns non-%NULL, iteration terminates and that value is returned. The
 * map function returns %NULL if all calls return %NULL.
 *
 * See also: im_slist_map().
 *
 * Returns: the result of iteration
 */
void *
vips_format_map(VSListMap2Fn fn, void *a, void *b)
{
	GSList *formats;
	void *result;

	formats = NULL;
	(void) vips_class_map_all(g_type_from_name("VipsFormat"),
		(VipsClassMapFn) format_add_class, (void *) &formats);

	formats = g_slist_sort(formats, (GCompareFunc) format_compare);
	result = im_slist_map2(formats, fn, a, b);
	g_slist_free(formats);

	return result;
}

/* Abstract base class for image formats.
 */

G_DEFINE_ABSTRACT_TYPE(VipsFormat, vips_format, VIPS_TYPE_OBJECT);

static void
vips_format_summary_class(VipsObjectClass *object_class, VipsBuf *buf)
{
	VipsFormatClass *class = VIPS_FORMAT_CLASS(object_class);

	VIPS_OBJECT_CLASS(vips_format_parent_class)
		->summary_class(object_class, buf);
	vips_buf_appends(buf, ", ");

	if (class->suffs) {
		const char **p;

		vips_buf_appends(buf, "(");
		for (p = class->suffs; *p; p++) {
			vips_buf_appendf(buf, "%s", *p);
			if (p[1])
				vips_buf_appends(buf, ", ");
		}
		vips_buf_appends(buf, ") ");
	}

	if (class->is_a)
		vips_buf_appends(buf, "is_a ");
	if (class->header)
		vips_buf_appends(buf, "header ");
	if (class->load)
		vips_buf_appends(buf, "load ");
	if (class->save)
		vips_buf_appends(buf, "save ");
	if (class->get_flags)
		vips_buf_appends(buf, "get_flags ");
}

static void
vips_format_class_init(VipsFormatClass *class)
{
	VipsObjectClass *object_class = (VipsObjectClass *) class;

	object_class->nickname = "format";
	object_class->description = _("VIPS file formats");
	object_class->summary_class = vips_format_summary_class;

	/* Hide from UI.
	 */
	object_class->deprecated = TRUE;
}

static void
vips_format_init(VipsFormat *object)
{
}

/**
 * vips_format_get_flags:
 * @format: format to test
 * @filename: file to test
 *
 * Get a set of flags for this file.
 *
 * Returns: flags for this format and file
 */
VipsFormatFlags
vips_format_get_flags(VipsFormatClass *format, const char *filename)
{
	return format->get_flags ? format->get_flags(filename) : 0;
}

/* VIPS format class.
 */

static const char *vips_suffs[] = { ".v", ".vips", NULL };

int
im_isvips(const char *filename)
{
	unsigned char buf[4];

	if (im__get_bytes(filename, buf, 4) == 4) {
		if (buf[0] == 0x08 && buf[1] == 0xf2 &&
			buf[2] == 0xa6 && buf[3] == 0xb6)
			/* SPARC-order VIPS image.
			 */
			return 1;
		else if (buf[3] == 0x08 && buf[2] == 0xf2 &&
			buf[1] == 0xa6 && buf[0] == 0xb6)
			/* INTEL-order VIPS image.
			 */
			return 1;
	}

	return 0;
}

static int
file2vips(const char *filename, IMAGE *out)
{
	IMAGE *im;

	if (!(im = im_open_local(out, filename, "r")) ||
		im_copy(im, out))
		return -1;

	return 0;
}

static VipsFormatFlags
vips_flags(const char *filename)
{
	VipsFormatFlags flags;
	unsigned char buf[4];

	flags = VIPS_FORMAT_PARTIAL;

	if (im__get_bytes(filename, buf, 4) == 4 &&
		buf[0] == 0x08 &&
		buf[1] == 0xf2 &&
		buf[2] == 0xa6 &&
		buf[3] == 0xb6)
		flags |= VIPS_FORMAT_BIGENDIAN;

	return flags;
}

/* Vips format adds no new members.
 */
typedef VipsFormat VipsFormatVips;
typedef VipsFormatClass VipsFormatVipsClass;

static int
vips_format_vips_save(VipsImage *image, const char *filename)
{
	return vips_image_write_to_file(image, filename, NULL);
}

static void
vips_format_vips_class_init(VipsFormatVipsClass *class)
{
	VipsObjectClass *object_class = (VipsObjectClass *) class;
	VipsFormatClass *format_class = (VipsFormatClass *) class;

	object_class->nickname = "vips";
	object_class->description = _("VIPS");

	format_class->priority = 200;
	format_class->is_a = im_isvips;
	format_class->header = file2vips;
	format_class->load = file2vips;
	format_class->save = vips_format_vips_save;
	format_class->get_flags = vips_flags;
	format_class->suffs = vips_suffs;
}

static void
vips_format_vips_init(VipsFormatVips *object)
{
}

G_DEFINE_TYPE(VipsFormatVips, vips_format_vips, VIPS_TYPE_FORMAT);

/* Called on startup: register the base vips formats.
 */
void
im__format_init(void)
{
	extern GType vips_format_csv_get_type(void);
	extern GType vips_format_ppm_get_type(void);
	extern GType vips_format_analyze_get_type(void);
	extern GType vips_format_rad_get_type(void);

	vips_format_vips_get_type();
#ifdef HAVE_JPEG
	extern GType vips_format_jpeg_get_type(void);
	vips_format_jpeg_get_type();
#endif /*HAVE_JPEG*/
#if defined(HAVE_PNG) || defined(HAVE_SPNG)
	extern GType vips_format_png_get_type(void);
	vips_format_png_get_type();
#endif /*HAVE_PNG*/
#ifdef HAVE_LIBWEBP
	extern GType vips_format_webp_get_type(void);
	vips_format_webp_get_type();
#endif /*HAVE_LIBWEBP*/
	vips_format_csv_get_type();
	vips_format_ppm_get_type();
	vips_format_analyze_get_type();
#ifdef HAVE_OPENEXR
	extern GType vips_format_exr_get_type(void);
	vips_format_exr_get_type();
#endif /*HAVE_OPENEXR*/
#ifdef HAVE_MATIO
	extern GType vips_format_mat_get_type(void);
	vips_format_mat_get_type();
#endif /*HAVE_MATIO*/
#ifdef HAVE_CFITSIO
	extern GType vips_format_fits_get_type(void);
	vips_format_fits_get_type();
#endif /*HAVE_CFITSIO*/
	vips_format_rad_get_type();
#ifdef HAVE_MAGICK
	extern GType vips_format_magick_get_type(void);
	vips_format_magick_get_type();
#endif /*HAVE_MAGICK*/
#ifdef HAVE_TIFF
	extern GType vips_format_tiff_get_type(void);
	vips_format_tiff_get_type();
#endif /*HAVE_TIFF*/
	extern GType vips_format_openslide_get_type(void);
	vips_format_openslide_get_type();
	extern GType vips_format_nifti_get_type(void);
	vips_format_nifti_get_type();
}

/* Can this format open this file?
 */
static void *
format_for_file_sub(VipsFormatClass *format,
	const char *name, const char *filename)
{
	if (format->is_a) {
		if (format->is_a(filename))
			return format;
	}
	else if (im_filename_suffix_match(filename, format->suffs))
		return format;

	return NULL;
}

/**
 * vips_format_for_file:
 * @filename: file to find a format for
 *
 * Searches for a format you could use to load a file.
 *
 * See also: vips_format_read(), vips_format_for_name().
 *
 * Returns: a format on success, %NULL on error
 */
VipsFormatClass *
vips_format_for_file(const char *filename)
{
	char name[FILENAME_MAX];
	char options[FILENAME_MAX];
	VipsFormatClass *format;

	/* Break any options off the name ... eg. "fred.tif:jpeg,tile"
	 * etc.
	 */
	im_filename_split(filename, name, options);

	if (!im_existsf("%s", name)) {
		im_error("VipsFormat", _("file \"%s\" not found"), name);
		return NULL;
	}

	if (!(format = (VipsFormatClass *) vips_format_map(
			  (VSListMap2Fn) format_for_file_sub,
			  (void *) filename, (void *) name))) {
		im_error("VipsFormat",
			_("file \"%s\" not a known format"), name);
		return NULL;
	}

	return format;
}

/* Can we write this filename with this format? Ignore formats without a save
 * method.
 */
static void *
format_for_name_sub(VipsFormatClass *format, const char *name)
{
	if (format->save &&
		im_filename_suffix_match(name, format->suffs))
		return format;

	return NULL;
}

/**
 * vips_format_for_name:
 * @filename: name to find a format for
 *
 * Searches for a format you could use to save a file.
 *
 * See also: vips_format_write(), vips_format_for_file().
 *
 * Returns: a format on success, %NULL on error
 */
VipsFormatClass *
vips_format_for_name(const char *filename)
{
	VipsFormatClass *format;

	if (!(format = (VipsFormatClass *) vips_format_map(
			  (VSListMap2Fn) format_for_name_sub,
			  (void *) filename, NULL))) {
		im_error("VipsFormat",
			_("\"%s\" is not a supported image format."),
			filename);

		return NULL;
	}

	return format;
}

/**
 * vips_format_read:
 * @filename: file to load
 * @out: write the file to this image
 *
 * Searches for a format for this file, then loads the file into @out.
 *
 * See also: vips_format_write().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_format_read(const char *filename, IMAGE *out)
{
	VipsFormatClass *format;

	if (!(format = vips_format_for_file(filename)) ||
		format->load(filename, out))
		return -1;

	return 0;
}

/**
 * vips_format_write:
 * @in: image to write
 * @filename: file to write to
 *
 * Searches for a format for this name, then saves @im to it.
 *
 * See also: vips_format_read().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_format_write(IMAGE *in, const char *filename)
{
	VipsFormatClass *format;

	if (!(format = vips_format_for_name(filename)) ||
		format->save(in, filename))
		return -1;

	return 0;
}
